As the world population ages, it is not uncommon to encounter patients who develop systemic lupus erythematosus (SLE) late in life. However, not much is known about SLE in this age group, but it clearly differs from younger onset disease in its epidemiologic, clinical and serological features; moreover, it is often misdiagnosed as drug-induced SLE or another rheumatic disease. As a result, a significant delay in its diagnosis is commonly observed. The choice of therapeutic agents in patients from this age group must also be very carefully considered. Immunosenescence, the development of CD8+ T-cell oligoclonal expansion and an abnormal apoptosis signaling pathway are some of the possible biologic mechanisms underlying late-onset SLE. Some misconceptions (fiction) are not uncommon in this subset of patients; they are gradually being replaced by facts as new data emerge. © 2008 Future Medicine Ltd.